<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - PostProcessing - GUI</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
  </body>
<!-- Import maps polyfill -->
<!-- Remove this when import maps will be widely supported -->
<script async src="https://unpkg.com/es-module-shims@1.3.6/dist/es-module-shims.js"></script>

<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js",
    "three/addons/": "../../examples/jsm/"
  }
}
</script>

<script type="module">
import * as THREE from 'three';
import {EffectComposer} from 'three/addons/postprocessing/EffectComposer.js';
import {RenderPass} from 'three/addons/postprocessing/RenderPass.js';
import {BloomPass} from 'three/addons/postprocessing/BloomPass.js';
import {FilmPass} from 'three/addons/postprocessing/FilmPass.js';
import {GUI} from 'three/addons/libs/lil-gui.module.min.js';

function main() {
  const canvas = document.querySelector('#c');
  const renderer = new THREE.WebGLRenderer({canvas});

  const fov = 75;
  const aspect = 2;  // the canvas default
  const near = 0.1;
  const far = 5;
  const camera = new THREE.PerspectiveCamera(fov, aspect, near, far);
  camera.position.z = 2;

  const scene = new THREE.Scene();

  {
    const color = 0xFFFFFF;
    const intensity = 2;
    const light = new THREE.DirectionalLight(color, intensity);
    light.position.set(-1, 2, 4);
    scene.add(light);
  }

  const boxWidth = 1;
  const boxHeight = 1;
  const boxDepth = 1;
  const geometry = new THREE.BoxGeometry(boxWidth, boxHeight, boxDepth);

  function makeInstance(geometry, color, x) {
    const material = new THREE.MeshPhongMaterial({color});

    const cube = new THREE.Mesh(geometry, material);
    scene.add(cube);

    cube.position.x = x;

    return cube;
  }

  const cubes = [
    makeInstance(geometry, 0x44aa88,  0),
    makeInstance(geometry, 0x8844aa, -2),
    makeInstance(geometry, 0xaa8844,  2),
  ];

  const composer = new EffectComposer(renderer);
  composer.addPass(new RenderPass(scene, camera));

  const bloomPass = new BloomPass(
      1,    // strength
      25,   // kernel size
      4,    // sigma ?
      256,  // blur render target resolution
  );
  composer.addPass(bloomPass);

  const filmPass = new FilmPass(
      0.35,   // noise intensity
      0.025,  // scanline intensity
      648,    // scanline count
      false,  // grayscale
  );
  filmPass.renderToScreen = true;
  composer.addPass(filmPass);

  function resizeRendererToDisplaySize(renderer) {
    const canvas = renderer.domElement;
    const width = canvas.clientWidth;
    const height = canvas.clientHeight;
    const needResize = canvas.width !== width || canvas.height !== height;
    if (needResize) {
      renderer.setSize(width, height, false);
    }
    return needResize;
  }

  const gui = new GUI();
  {
    const folder = gui.addFolder('BloomPass');
    folder.add(bloomPass.combineUniforms.strength, 'value', 0, 2).name('strength');
    folder.open();
  }
  {
    const folder = gui.addFolder('FilmPass');
    folder.add(filmPass.uniforms.grayscale, 'value').name('grayscale');
    folder.add(filmPass.uniforms.nIntensity, 'value', 0, 1).name('noise intensity');
    folder.add(filmPass.uniforms.sIntensity, 'value', 0, 1).name('scanline intensity');
    folder.add(filmPass.uniforms.sCount, 'value', 0, 1000).name('scanline count');
    folder.open();
  }

  let then = 0;
  function render(now) {
    now *= 0.001;  // convert to seconds
    const deltaTime = now - then;
    then = now;

    if (resizeRendererToDisplaySize(renderer)) {
      const canvas = renderer.domElement;
      camera.aspect = canvas.clientWidth / canvas.clientHeight;
      camera.updateProjectionMatrix();
      composer.setSize(canvas.width, canvas.height);
    }

    cubes.forEach((cube, ndx) => {
      const speed = 1 + ndx * .1;
      const rot = now * speed;
      cube.rotation.x = rot;
      cube.rotation.y = rot;
    });

    composer.render(deltaTime);

    requestAnimationFrame(render);
  }

  requestAnimationFrame(render);
}

main();
</script>
</html>

